Lubricated photographic element containing a mixture of higher fatty alcohols and higher fatty acids



Patented Mar. 11, 1952 LUBRICATED PHOTOGRAPHIC ELEMENT CONTAINING A MIXTURE OF HIGHER FATTY ALCOHOLS AND HIGHER FATTY ACIDS Willem P. M. J. Robijns, Mortsel-Antwerp, Belgium, assignor to Gevaert Photo-Producten N. V., Mortsel-Antwerp, Belgium,

of Belgium 21. company No Drawing. Application April 23, 1946, Serial No. 664,422. In Belgium March 21, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires March 21, 1964 8 Claims.

It is known that the most different defects upon photographic material, either during its manufacture, its treatment or even Whilst using the finished material, are caused by friction. Whilst coating the photographic matenal, friction produces static electricity, the discharge of which fogs by its sparks the light sensitive layer. An emulsion layer with a high frictioncoefiicient does not sufficiently slide on winding photographic film, whereby friction-marks and scratches appear upon the developed material. Source of spotted fog upon film is for instance a not sufficiently smooth moving of the film inside the photographic apparatus whilst taking the picture, and, upon paper during its treatment, a friction-resistance upon the emulsion-paper by sliding of the prints over each other.

Whilst projecting too, the film inside the apparatus should turn with the least possible friction; otherwise, the motion becomes irregular, which results in unstable pictures and an early damage of both the film support and emulsion layer.

Decrease of the friction-coefiicient of the sur face upon the finished negative pictures both of roll films and plates means a better resistance against damage by contact at a more or less high pressure.

Several means have been proposed to overcome these defects.

Thus it is known to protect the emulsion layers against mechanical damage by covering them with a protective layer, i. e. a thin transparent layer of gelatine or the like. This protective layer either may dissolve in the photographic baths or swell, whereby it gets permeable to the photographic treating baths.

For obtaining a sufficiently useful effect, a relatively thick protective layer sometimes is brought as a coat upon highly-sensitive emulsions. Thus in a soluble protective layer the complete removal is considerably slackened whereas in the second case no quick nor uniform penetration of the treating bath into the emulsion takes place, what results in an irregular development. The finished photographic picture, especially with vigorous emulsion, shows a matted aspect. Finally, both the slow penetration of the developer through the protective layer and the resulting prolonged developing time do not allow to use fully the sensitivity of the photographic material, so that a suitable protective layer in many cases means a sensitivity decrease.

As a further possibility to prevent damaging of film, particularly on running inside the photographic apparatuses, it is known to incorporate a small quantity of wax in the emulsion, in the upper layer and in the under layer as well. Wax, however, when technically applied, is brought with difficulty in a sufficiently finely-divided form and the resulting particles hardly can be emulsified stably.

Now the present invention has for its object a new process wherein all causes of frictiondefects are eliminated, characterizing itself in comparison with the formerly known methods by' a quite simple working. At the very moment of friction in or upon the photographic surface exposed to friction, a small quantity shall be present of the mixture consisting of neutralized fatty acids and fatty alcohols which is obtained by the saponification of esters of fatty acids and fatty alcohols. These saponifying products increase to a high degree the sliding coefiicient, involving a considerable improvement of the mechanical properties. On the other hand the way to form the active products is quite favorable to their application. Indeed, generated by the saponifying reaction in molecular state, the fatty alcohols which mainly are to be considered as the sliding active substances possess their largest activity. At the same time are produced as Well the fatty acids which by their emulsifying properties facilitate the emulsifying of the fatty alcohols to stable emulsions and moreover help to decrease the friction.

The saponified esters may be introduced into or onto the treated surface at any moment proper to the purpose in view and may take place either during the manufacture, the treatment or even in a specal following-up treatment of the photographic material. Thus for instance the saponified products may be added before coating to the usual solutions of the protective layers.

This way of applying allows to reduce substantially the thickness of the usual protective layer either upon film or paper. Besides saving binders, there is with treating baths the great advantage of penetrating in an easier and more uniform way through the protective layer up to the emulsion layer.

The saponifying products may be added to the photographic emulsion itself as well, whereby such improved mechanical properties of the emulsion surface are obtained that, on winding either the film or the paper, scratches or friction marks whatsoever are out of question.

It is of primary importance that the saponifying products of my invention quite facilitate the sliding of the photographic film inside the photographic apparatuses. For this purpose the products may be added to the protective layer, to the light sensitive emulsion and/or to a back layer solution; furthermore to one of the treating baths, for instance the developer or a special following-up bath. v

According to my invention the photographic layers are less liable to stick against each other.

This is amongst others for roll films of great practical value for instance to eliminate stickingof the roll film against the duplex band.

Example .1 .--Use of the sapom'fying products in photographic protective Zayers.-Myricyl palmitate is saponified at boiling temperature with an 8 per cent solution of NaOH and the excess of alkali is neutralized with hydrochloric acid. A quantity of 0.1 to 0.5 g. of the so-obtained rough mixture is added to the solution of protective layer required for 1 square yard protective layer.

Example 2.Saponifying product in the photographic emulsion itself.Cerylcerotine is saponifled in a 10 per cent solution of NaOH, whereafter the excess of alkali is neutralized with hydrochloric acid. This rough saponifying emulsion is directly used in a photographic emulsion so that about 0.5 to 2.5 g. per square yard emulsion layer are present.

Example 3.The saponifying products either may be added to one of the treating baths as for instance the developing bath or the wash- Water, or to a special following-up bath. A proof of these products confined between 0.5 and 5 per cent per liter turned out to be quite active.

I claim: 1. A photographic material comprising a support coated with several colloid layers of which at least one layer contains a silver halide, at

,- least one outer layer of said colloid layers containing a homogeneous suspension in Water of at least one completely saponified ester of a saturated higher fatty alcohol and a saturatedhigher fatty acid in the presence of both a base and its salts.

2. A photographic material comprising a sup-' port coated With several colloid layers of which 'at least one layer contains a silver halide, the 'outer silver halide emulsion .layer containing a homogeneous suspension in water of at least 'one completely saponified ester of a saturated higher fatty alcohol and a saturated higher fatty acid in the presence of both a base and its salts.

3. A photographic material comprising a support coated with several colloid layers of which at least one layer contains a silver halide, the protective layer containing a homogeneous suspension in water of at least one completely saponified ester of a saturated higher fatty al- :cohol and a saturated higher fatty acid in the presence of both a base and its salts.

4. A photographic material comprising a support coated with several colloidlayers of which at least one layer contains a silver halide, the outer back layer of said colloid layers containing a homogeneous suspension in water of at least one completely saponified ester of a saturated higher fatty alcohol and a saturated higher fatty acid in the presence of both a base and its salts.

5. An image bearing motion-picture film, comprising a support coated with several colloid layers of which at least one layer bears an image, at least one outer layer of said colloid layers containing a homogeneous suspension in water of at least one completely saponified ester of a saturated higher fatty alcohol and a saturated higher fatty acid in the presence of both a base and its salts.

6. An image bearing motion-picture film, comprising a support coated with several colloid layers of which at least one layer bears an image, the outer image bearing layers containing a ho mogeneous suspension in water of at least one completelysaponified ester of a saturated higher fatty alcohol and a saturated higher fatty acid in the presence of both a base and its salts.

7. An image bearing motion-picture film, comprising a support coated with several colloid layers of which at least one layer bears an image, the protective layer containing a homogeneous suspension in water of at least one completely saponified ester of a saturated higher fatty alcohol and a saturated higher fatty acid in the presence of both a base and its salts.

8. An image bearing motion-picture film, comprising a sup-port coated with several colloid layers of which at least one layer bears an image, the outer back layers of said colloid layers containing a homogeneous suspension in water of at least one completely saponified ester of a saturated higher fatty alcohol and a saturated higher fatty acid in the presence of both a base and its salts.

" WILLEM P. M. J. ROBIJNS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain of 1913 

1. A PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT COATED WITH SEVERAL COLLOID LAYERS OF WHICH AT LEAST ONE LAYER CONTAINS A SILVER HALIDE, AT LEAST ONE OUTER LAYER OF SAID COLLOID LAYERS CONTAINING A HOMOGENEOUS SUSPENSION IN WATER OF AT LEAST ONE COMPLETELY SAPONIFIED ESTER OF A SATURATED HIGHER FATTY ALCOHOL AND A SATURATED HIGHER FATTY ACID IN THE PRESENCE OF BOTH A BASE AND ITS SALTS. 